The results obtained from the research on the behaviour of fences (solid and porous) in the protection against particulated material emission to the atmosphere from open storage piles,are presented. This research was ...The results obtained from the research on the behaviour of fences (solid and porous) in the protection against particulated material emission to the atmosphere from open storage piles,are presented. This research was carried out through computational fluid dynamics (CFD) simulation by software Ansys CFX-10.0 in 3D,with K-epsilon being considered in the turbulence model. The efficiency of the use of porous fences as a protection against the wind flow,which interacts with an open storage pile,is shown. The use of these fences (when porosity is ε=30%) allows the reduction of wind flow velocity which interacts with the pile in comparison with the case of no use of fences (when porosity is 100%). In addition,the use of porous fences makes the velocity vortex,which is formed between the solid fence (ε=0%) and the pile,disappear,reducing the particle emission to the atmosphere by 78%.展开更多
A decomposition model was applied to study the resource-saving and environment-friendly effects of air pollutant emissions(taking industrial SO2 emission as an example) in China.From the results,it is found that 38.93...A decomposition model was applied to study the resource-saving and environment-friendly effects of air pollutant emissions(taking industrial SO2 emission as an example) in China.From the results,it is found that 38.93% and 61.07% are contributed to environment-friendly and resource-saving effects,respectively,by the dramatic decrease in industrial SO2 emission density(nearly 70% from 2001 to 2010).This indicates that China has achieved important progress during the 11th FYP(five-year plan) compared with the 10th FYP.A simultaneous equations model was also employed to analyze the influencing factors by using data from 30 provinces in China.The results imply that the influence of environmental regulation on environment-friendly effect is not obvious during the 10th FYP but obvious during the 11th FYP.Thus,the government should continue promoting the environment-friendly effect by further enhancing environmental regulation and strengthening the role of environmental management.展开更多
In addition to the conventional Franklin Rod,many non-conventional air terminals are being used as lightning protection devices.As cited in previous works,these non-conventional devices emit space charge in the vicini...In addition to the conventional Franklin Rod,many non-conventional air terminals are being used as lightning protection devices.As cited in previous works,these non-conventional devices emit space charge in the vicinity of the terminals during the process of lightning stroke.A number of factors affect the performance of these lightning protection devices,among them are geometry and dimension of the devices,location of the device above the ground,height of the cloud above the ground,and polarity of the lightning stroke.The performance of these lightning protection devices has been a topic of discussion by researchers for many years.Some studies focused on the magnitude of emission current from these devices as a criterion to evaluate their performances.The critical flashover voltage(CFO)between the devices and a metal screen simulating cloud can also be used as another criterion to evaluate the performance of the devices.Laboratory measurements were conducted in controlled conditions on different types of lightning protection devices to compare their performance.Four different types of devices were used in the present study:Franklin Rod,TerraStat models TS 100,TS 400,and Spline Ball Ionizer.The study focused on the CFO voltage of the air gap between devices and the metal screen.The CFO voltage was evaluated using standard switching and lightning impulses.The measurements were recorded for positive as well as negative polarity.The air gap between the devices and metal screen was selected at 2 m and 3 m.The results obtained provide a better understanding of the electrical performance of lightning protection devices.展开更多
运用CiteSpace对Web of Science和中国知网相关文献进行梳理,分析该领域的研究热点与进展.结果表明:国内外发文量都在不断增加.2013年后,发文量增长迅速,国外增速明显快于国内;国外文献作者和机构形成了以美国各大高校为中心的较强合作...运用CiteSpace对Web of Science和中国知网相关文献进行梳理,分析该领域的研究热点与进展.结果表明:国内外发文量都在不断增加.2013年后,发文量增长迅速,国外增速明显快于国内;国外文献作者和机构形成了以美国各大高校为中心的较强合作网络关系,核心研究作者发文量达39%.国内文献作者和机构联系较弱,呈多中心分散式结构,核心研究作者发文量仅占8%;关键词可视化表明国内外研究同步性较强,均以环境暴露的健康影响和疾病负担研究为基础,国外侧重具体影响机制与联系及风险评估研究,国内更关注影响因素及政策效益剖析;国外研究从环境暴露对健康终点影响发展到协同适应策略及复杂模型构建,目前全球负担和颗粒物质减排是研究热点.国内研究从气候变化和大气污染对健康的影响评估发展到协同治理对策及健康风险,当前减缓气候变化及减污降碳的健康协同效益研究是热点.将来针对气候变化和大气污染导致的健康问题及敏感区域、公共健康效应时空规律的识别和明晰是重点,健康风险评估模型构建与早期预警系统的开发应用也迫在眉睫.展开更多
基金the Spanish Ministry of Science and Education that granted these researches through the project CTM2005-00187/TECNO "Prediction Models and Prevention Systems in the Particle Atmospheric Pollution in an Industrial Environment" carried out at Oviedo University
文摘The results obtained from the research on the behaviour of fences (solid and porous) in the protection against particulated material emission to the atmosphere from open storage piles,are presented. This research was carried out through computational fluid dynamics (CFD) simulation by software Ansys CFX-10.0 in 3D,with K-epsilon being considered in the turbulence model. The efficiency of the use of porous fences as a protection against the wind flow,which interacts with an open storage pile,is shown. The use of these fences (when porosity is ε=30%) allows the reduction of wind flow velocity which interacts with the pile in comparison with the case of no use of fences (when porosity is 100%). In addition,the use of porous fences makes the velocity vortex,which is formed between the solid fence (ε=0%) and the pile,disappear,reducing the particle emission to the atmosphere by 78%.
基金Project(201009066)supported by the R&D Special Fund for Public Welfare of the Ministry of Finance and Ministry of Science and Technology of China
文摘A decomposition model was applied to study the resource-saving and environment-friendly effects of air pollutant emissions(taking industrial SO2 emission as an example) in China.From the results,it is found that 38.93% and 61.07% are contributed to environment-friendly and resource-saving effects,respectively,by the dramatic decrease in industrial SO2 emission density(nearly 70% from 2001 to 2010).This indicates that China has achieved important progress during the 11th FYP(five-year plan) compared with the 10th FYP.A simultaneous equations model was also employed to analyze the influencing factors by using data from 30 provinces in China.The results imply that the influence of environmental regulation on environment-friendly effect is not obvious during the 10th FYP but obvious during the 11th FYP.Thus,the government should continue promoting the environment-friendly effect by further enhancing environmental regulation and strengthening the role of environmental management.
文摘In addition to the conventional Franklin Rod,many non-conventional air terminals are being used as lightning protection devices.As cited in previous works,these non-conventional devices emit space charge in the vicinity of the terminals during the process of lightning stroke.A number of factors affect the performance of these lightning protection devices,among them are geometry and dimension of the devices,location of the device above the ground,height of the cloud above the ground,and polarity of the lightning stroke.The performance of these lightning protection devices has been a topic of discussion by researchers for many years.Some studies focused on the magnitude of emission current from these devices as a criterion to evaluate their performances.The critical flashover voltage(CFO)between the devices and a metal screen simulating cloud can also be used as another criterion to evaluate the performance of the devices.Laboratory measurements were conducted in controlled conditions on different types of lightning protection devices to compare their performance.Four different types of devices were used in the present study:Franklin Rod,TerraStat models TS 100,TS 400,and Spline Ball Ionizer.The study focused on the CFO voltage of the air gap between devices and the metal screen.The CFO voltage was evaluated using standard switching and lightning impulses.The measurements were recorded for positive as well as negative polarity.The air gap between the devices and metal screen was selected at 2 m and 3 m.The results obtained provide a better understanding of the electrical performance of lightning protection devices.
文摘运用CiteSpace对Web of Science和中国知网相关文献进行梳理,分析该领域的研究热点与进展.结果表明:国内外发文量都在不断增加.2013年后,发文量增长迅速,国外增速明显快于国内;国外文献作者和机构形成了以美国各大高校为中心的较强合作网络关系,核心研究作者发文量达39%.国内文献作者和机构联系较弱,呈多中心分散式结构,核心研究作者发文量仅占8%;关键词可视化表明国内外研究同步性较强,均以环境暴露的健康影响和疾病负担研究为基础,国外侧重具体影响机制与联系及风险评估研究,国内更关注影响因素及政策效益剖析;国外研究从环境暴露对健康终点影响发展到协同适应策略及复杂模型构建,目前全球负担和颗粒物质减排是研究热点.国内研究从气候变化和大气污染对健康的影响评估发展到协同治理对策及健康风险,当前减缓气候变化及减污降碳的健康协同效益研究是热点.将来针对气候变化和大气污染导致的健康问题及敏感区域、公共健康效应时空规律的识别和明晰是重点,健康风险评估模型构建与早期预警系统的开发应用也迫在眉睫.
